.container {
    position: relative;
    width: 1000px;
    height: 360px;
    margin: 20px auto;
}

.container .wrapper {
    position: absolute;
    width: 100%;
    height: 100%;
}

.container .wrapper .slide {
    position: absolute; /* 让所有的图叠加 */
    z-index: 0;
    opacity: 0;

    width: 100%;
    height: 100%;
}

/* 默认显示第一个子元素 */
.container .wrapper .slide:nth-of-type(1) {
    z-index: 1;
    opacity: 1;
}

.container .wrapper .slide img {
    display: block;
    width: 100%;
    height: 100%;
}

.container .focus {
    position: absolute;
    z-index: 999;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);

    height: 12px;
    padding: 4px;
    background: rgba(0, 0, 0, .7);
    border-radius: 10px;
    font-size: 0; /* 由于子元素li转为行内块 */
}

.container .focus li {
    display: inline-block;
    width: 12px;
    height: 12px;
    margin: 0 4px;
    background-color: #fff;
    border-radius: 50%;
    cursor: pointer; /* 手势 */
}

.container .focus li.active {
    background-color: red;
}

.container .arrow {
    position: absolute;
    z-index: 999;
    top: 50%;
    transform: translateY(-50%);

    display: none;
    width: 30px;
    height: 45px;
    opacity: .3;
    background: url(../img/pre.png);
}

.container .arrow:hover {
    opacity: .7;
}

.container .arrow.arrowLeft {
    left: 0;
    background-position: 0 0;
}

.container .arrow.arrowRight {
    right: 0;
    background-position: -50px 0;
}